1. Field of the Invention
The present invention relates to electronic components and, in particularly, to a four-terminal electronic component including four external electrodes each including a portion extending to a main surface and that are arranged such that a shape defined by joining the centers of the four external electrodes on the main surface with a substantially straight line is substantially square.
2. Description of the Related Art
Electronic devices, such as a cellular phone and a portable music player, have become smaller in recent years, and a mounting board implemented on the electronic device has become smaller. As a result, the mounting area of the mounting board has also become smaller. Accordingly, demand for miniaturization of a ceramic electronic component mounted on a mounting board is increasing, and an array ceramic electronic component in which ceramic components are packaged in one chip is often used. The use of such an array ceramic electronic component can reduce both the mounting space and mounting cost, in comparison to when a plurality of components is mounted.
One specific example of such an array ceramic electronic component is a capacitor module that includes a plurality of capacitor units disclosed in Japanese Unexamined Patent Application Publication No. 2004-14687. A perspective view of the capacitor module disclosed in Japanese Unexamined Patent Application Publication No. 2004-14687 is illustrated in FIG. 10.
As illustrated in FIG. 10, a capacitor module 100 is of the four-terminal type. Specifically, the capacitor module 100 includes a substantially rectangular parallelepiped array body 101 made of, for example, ceramic. First and second capacitor units (not shown) are disposed substantially in parallel with each other in the array body 101.
Side electrodes 102a and 103a are disposed at a first side surface 101a of the array body 101 such that they are spaced apart from each other in the longitudinal direction. Side electrodes 102b and 103b are disposed at a second side surface 101b of the array body 101 such that they are spaced apart from each other in the longitudinal direction. The upper end of each of the side electrodes 102a, 103a, 102b, and 103b extends to a first main surface 101c. 
Of these side electrodes 102a, 103a, 102b, and 103b, the side electrodes 102a and 102b are connected to the first capacitor unit, and the remaining side electrodes 103a and 103b are connected to the second capacitor unit.
For the capacitor module 100 illustrated in FIG. 10, the side electrodes 102a and 102b positioned at a first side in the longitudinal direction and the side electrodes 103a and 103b positioned at a second side in the longitudinal direction are connected to different capacitor units. Thus, at the time of mounting the capacitor module 100, the orientation of the capacitor module 100 matters. Accordingly, one possible way to determine the orientation of an electronic component is determination of the positional relationship among the portions of the side electrodes on the first main surface 101c by the use of an imaging device (e.g., a camera).
This determination is effective if, on the first main surface 101c, the center-to-center distance L10 between the side electrodes 102a and 103a is different from the center-to-center distance L11 between the side electrodes 102a and 102b, for example.
However, as illustrated in FIG. 10, when the distance L10 is substantially the same as the distance L11, because the four side electrodes are positioned at substantially the same locations both when the side surfaces of the array body lie along the horizontal direction and when the side surfaces lie along the vertical direction, there is a problem in that determining the orientation of the capacitor module 100 is difficult.
Another possible way to determine the orientation of the capacitor module 100 is determination of the shape of the portions of the side electrodes on the first main surfaces by the use of an imaging device. However, the additional determination of the shape of the side electrodes requires significantly high precision for the imaging device and also makes the determination step complicated and difficult.